1. Field of the Invention
The present invention broadly relates to insulation as utilized in building structures, primarily of a metal material, and in which it is desired to provide, either during initial construction, or subsequent to complete construction of the building, having mounted thereover a roof, usually of metal, as an addition, a vapor barrier for that insulation. The vapor barrier serves to preclude penetration of moisture into insulation material, from the interior of the building. The vapor barrier of the invention is applied externally of insulation within the building, to protect the insulation from moisture and/or humidity.
The invention is directed primarily to metal buildings utilizing metal roof structures having therebelow insulation material such as fiberglass, or others, which is supported in various known manners. Obviously the features of the invention are more broadly applicable than as specifically applied to special types or construction of metal buildings.
Numerous attempts have been made to devise a material structure, which can be referred to as a vapor barrier, and which is applied externally to insulation within a building, primarily of metal, to protect the insulation from moisture or humidity. Some known constructions have attempted to solve multiple problems existing in the art. It is essential, however, that the insulation be protected by a vapor barrier from moisture penetration, and which is preferably at the same time fire retardant, and must have a desired perm rating, which is a measure of how much moisture vapor can pass through the barrier to the insulation and which will be satisfactory in the industry. Industry heretofore has provided different facing types which on an industrial insulation essentially prevent diminishing, or complete destruction of the insulating value of insulating material due to the insulation becoming moist or wet.
A primary consideration of the present invention concerns the metal building insulation market. Metal buildings, subsequent to World War II, have been substantially increasing, many of them having little or no insulation. Current practice is to insulate the metal building just prior to the roof sheets being applied. Faced insulation of some constructions is usually rolled over the purlins, a type of supporting beam, and then the external flat roof sheets are placed over the insulation. These sheets trap or secure the insulation and it then becomes permenant part of the building.